1. Field of the Invention
The invention relates to a vehicular drive assist system that analyzes information collected from a vehicle and sends results of the analysis to the vehicle and/or another vehicle and, more particularly, to a vehicular drive assist system and a vehicular drive assist method that improve the vehicle running characteristics and the vehicle driver's feeling of safety.
2. Description of the Related Art
There is a known system that predicts traffic congestion situations on the basis of position information sent from vehicles to a communication center, and the like (e.g., see Japanese Patent Application Publication No. JP-A-2002-251698 and No. JP-A-2003-302229).
A navigation system that searches for a route while taking the ease of travel of roads into consideration is also known (e.g., see Japanese Patent Application Publication No. JP-A-2003-279365).
The aforementioned system that predicts traffic congestion situations is a system that grasps traffic congestion situations of roads from the collected position information and time information. However, the aforementioned system is not able to recognize the ease of travel of each road that will be experienced if the road is actually traveled by the vehicle.
In the aforementioned navigation system, a road with high running speeds is termed “high-speed road” that is easy to travel through, and it is judged whether or not a road is a high-speed road uniformly on the basis of road lengths between traffic signals, road lengths between intersections, whether or not the road is a separated inbound/outbound line road, whether the road is a single-path road with a center divider, the number of lanes of the road, or combinations thereof.
Parameters indicating physical road configurations as mentioned above can easily be acquired from the map information as well. However, it is impossible to judge the actual ease of travel of a road solely from such parameters. For example, a road with heavy on-street parking every day, an intersection with frequent incidents of vehicles stopping to turn right, a spot with many occurrences of a pedestrian running into the road, an intersection with a blocked view due to buildings or the like, a road with many bumps and dips, a road that often becomes icy on a winter morning, etc. Such needs for attention or ease of travel during the actual running of the vehicle cannot be sufficiently grasped unless the road is actually traveled through in the vehicle.
In other words, there is a risk that the aforementioned navigation system may determine that a road that actually cannot be said to be easy to travel through is an easy-to-travel road, apart from the actual circumstances. If such an incorrect result of determination is used for a vehicle control or a route search, adverse effect can be given to the vehicle running characteristics, or the driver can be made anxious.